How severe is CVE-2021-21551?

CVE-2021-21551 has a CVSS score of 8.8/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2021-21551?

Affected package information for CVE-2021-21551 is not yet fully mapped. Check the official advisory links for details.

How do I fix CVE-2021-21551?

No fixed version has been published for CVE-2021-21551 yet. Monitor the advisory for updates, apply mitigations recommended by the vendor, and use O3 Security to track when a fix becomes available in your stack.

Is CVE-2021-21551 actively exploited in the wild?

Yes. There are 21 known exploit references for CVE-2021-21551, including 1 documented proof-of-concept exploit on Exploit-DB and 13 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2021-21551?

CVE-2021-21551 has an EPSS (Exploit Prediction Scoring System) score of 74.5%, placing it in the 99th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. A score above 50% indicates significantly elevated exploitation risk — immediate patching is strongly recommended.

Is CVE-2021-21551 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2021-21551 (Dell dbutil Driver Insufficient Access Control Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2022-03-31. CISA required all US federal civilian agencies to remediate this vulnerability by 2022-04-21. The required action was: Apply updates per vendor instructions. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

What type of vulnerability is CVE-2021-21551?

CVE-2021-21551 is classified as CWE-782 (CWE-782). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

Which products and versions are affected by CVE-2021-21551?

CVE-2021-21551 affects dell dbutil. Check the affected-products list on this page against your deployed version to confirm exposure.

When was CVE-2021-21551 published, and has it been updated?

CVE-2021-21551 was published on May 4, 2021 and was last updated on October 28, 2025. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CISA KEV·Added 2022-03-31 — agencies required to remediate by 2022-04-21

CVE-2021-21551

HIGH

Dell dbutil_2_3.sys driver contains an insufficient access control vulnerability which may lead to escalation of privileges, denial of service, or information disclosure. Local authenticated…

Published

May 4, 2021

Updated

Oct 28, 2025

Affected

0 pkgs

Patched

None yet

Exploits

21 known

EPSS Exploitation Probability

via FIRST.org ↗

74.5%probability of exploitation in next 30 days

Very High Risk99th percentile+3.11%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Description

Dell dbutil_2_3.sys driver contains an insufficient access control vulnerability which may lead to escalation of privileges, denial of service, or information disclosure. Local authenticated user access is required.

Affected Products

1 product · 1 configurations

Application

dbutildell

≤ 2.3

range

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

EDB-49893localwindows

DELL dbutil_2_3.sys 2.3 - Arbitrary Write to Local Privilege Escalation (LPE)

by Paolo Stagno · May 21, 2021

Exploit-DB Source

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2021-21551 in your stack?

O3 detects CVE-2021-21551 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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